def mergeSort(arr):
    import math
    if(len(arr)<2):
        return arr
    middle = math.floor(len(arr)/2)
    left, right = arr[0:middle], arr[middle:]
    #print(left,right)
    return merge(mergeSort(left), mergeSort(right))

def merge(left,right):
    result = []
    while left and right:
        if left[0] <= right[0]:
            result.append(left.pop(0))
        else:
            result.append(right.pop(0))
    while left:
        result.append(left.pop(0))
    while right:
        result.append(right.pop(0))
    print(result)
    return result

arr = mergeSort([11,21,33,44,22,1,2,3,4,5,6,7,8,9])
print(arr)